Osteochondritis dissecans (OCD) is a problem affecting the joint with softening and detachment of the cartilage and bone. It affects boys twice as often as girls. The highest rates seem to occur among boys between the ages of 10 and 15 years.
It's hard to predict what will happen with this disease. Doctors would say it has a "guarded prognosis." Skeletal maturity at the time of diagnosis is the best predictor of outcome. The younger the patient, the better the chances for bone healing and recovery. Nonsurgical treatment is more likely to work for this group compared with older (adult) patients.
Patients with a stable joint have a better chance for a good outcome. With a stable joint there may be a fragment of damaged bone and cartilage, but it has not torn away from the joint surface. Smaller lesions do better than large ones. Damage to the weight-bearing surface of the joint is less likely to recover with nonsurgical treatment.
There's a large wait-and-see component to this condition. There's no way to say for sure he'll be back on the team next year. Encourage him to follow his doctor's advice carefully. This can help ensure his successful return to the team.